Prior to installing a head gimbal assembly (HGA) into a disc drive, it is desirable to dynamically test the functionality of the read and write transducers that reside on the HGA to determine if the HGA is defective. Testing is generally performed using HGA tester that includes a mounting fixture for supporting the HGA as well as a rotatable test disc. Such testing can include preliminary activities to align, configure, and prepare the HGA for testing, followed by the actual dynamic electrical test of the HGA.
During a dynamic electrical test procedure, the HGA is mounted on the mounting fixture of an HGA tester that supports the HGA throughout the testing process. For example, an operator may manually place the HGA into an alignment tool that sets the orientation of the HGA to an intermediate mounting fixture. The HGA is then loaded onto the rotating test disc such that the head of the HGA is suspended above the test disc by the air-bearing formed between the head and the disk. The HGA is then subjected to dynamic electrical testing, which may include, e.g., reading and writing to the test disc as well as monitoring for undesirable contact between the head and the test disc.
An HGA tester must be at least capable of holding the HGA on-track for a given track density of a product, which is commonly measured in tracks-per-inch (TPI). As track densities in disc drives increase, it becomes more difficult to provide HGA testers capable of holding the HGA on-track during testing.